Anyone remember the Kara who co-starred in that Superman: Aliens mini-series? It seemed like she was being groomed to be Supergirl, but she was never seen outside of that series. That was probably because Peter David took over Matrix Supergirl and revamped her -- and then DC finally decided to just bring back Kara Zor-El. But the Kara in Aliens was an offshoot of Kryptonians -- and thus would have had classic Super powers if she ever found her way to Earth.
A quick Google search shows that CBR recently did an article discussing this series -- and how Dan Jurgens wanted to make her Supergirl, but Mike Carlin (ugh) said no because of Matrix Supergirl. I would guess Aliens Kara is outside of canon, and with classic Kara back -- doesn't really have relevance, but I did like that Kara -- and that origin would have been preferable to the kinda (eww) Loeb/Turner origin.
https://www.cbr.com/superman-aliens-...new-supergirl/